Effect of smoking on breast cancer in carriers of mutant BRCA1 or BRCA2 genes.

BACKGROUND: Smoking has carcinogenic effects, and possibly antiestrogenic effects as well, but it has not been found to be a risk factor for breast cancer in women in the general population. However, hereditary breast cancer is primarily a disease of premenopausal women, and interactions between genes and hormonal and environmental risk factors may be particularly important in this subgroup. METHODS: We conducted a matched case-control study of breast cancer among women who have been identified to be carriers of a deleterious mutation in either the BRCA1 or the BRCA2 gene. These women were assessed for genetic risk at one of several genetic counseling programs for cancer in North America. Information about lifetime smoking history was derived from a questionnaire routinely administered to women who were found to carry a mutation in either gene. Smoking histories of case subjects with breast cancer and age-matched healthy control subjects were compared. Odds ratios for developing breast cancer were determined for smokers versus nonsmokers by use of conditional logistic regression for matched sets after adjustment for other known risk factors. RESULTS: Subjects with BRCA1 or BRCA2 gene mutations and breast cancer were significantly more likely to have been nonsmokers than were subjects with mutations and without breast cancer (two-sided P = .007). In a multivariate analysis, subjects with BRCA1 or BRCA2 mutations who had smoked cigarettes for more than 4 pack-years (i.e., number of packs per day multiplied by the number of years of smoking) were found to have a lower breast cancer risk (odds ratio = 0.46, 95% confidence interval = 0.27-0.80; two-sided P = .006) than subjects with mutations who never smoked. CONCLUSIONS: This study raises the possibility that smoking reduces the risk of breast cancer in carriers of BRCA1 or BRCA2 gene mutations.

A common mutation in BRCA2 that predisposes to a variety of cancers is found in both Jewish Ashkenazi and non-Jewish individuals.

Recent studies have identified mutations in the breast and (ovarian cancer susceptibility gene 2 (BRCA2), one which has been found in the germline of several males and one female affected with breast cancer. To establish the carrier frequency of this mutation in a large population of individuals affected with cancer, we evaluated constitutional DNA isolated from 83 individuals diagnosed with breast cancer and 93 diagnosed with ovarian cancer at any age, 42 of whom reported a family history of cancer. Using a simple allele-specific PCR-based nonradioactive method, we detected a total of eight individuals (4.5%) carrying a 1-bp deletion at nucleotide 6174 of the BRCA2 gene (6174delT). The age of disease onset in the mutant allele carriers was highly variable and typically late onset (41-72 years for breast cancer and 48-73 years for ovarian cancer). Evaluation of family histories for the eight mutant allele carriers revealed that several individuals had significant cancer histories that included, in addition to breast and/or ovarian cancer, an increased incidence of colon, esophageal, pancreatic, stomach, and hematopoietic cancers. Interestingly, seven of the eight individuals were of Ashkenazi Jewish descent. Haplotype data for the mutant allele carriers using markers spanning the region of the BRCA2 gene on chromosome 13ql2-ql3 suggest that only two of the confirmed Jewish Ashkenazi individuals share a single common ancestry, indicating several independent origins for this mutation. These data provide evidence for the presence of a specific BRCA2 mutation which has its origins in both Jewish Ashkenazi and non-Jewish populations. The observed overrepresentation of specific mutations within a subgroup of the general population may eventually help contribute to the development of inexpensive and routine tests such as the one described in our study.

The I1307K APC mutation does not predispose to colorectal cancer in Jewish Ashkenazi breast and breast-ovarian cancer kindreds.

An increased incidence of colorectal cancer has been observed in breast and breast-ovarian cancer syndrome families, including those of Ashkenazi origin. Recently, a germ-line missense mutation in the APC gene, I1307K, was identified that may indirectly cause colorectal cancer in Ashkenazi Jews. To determine whether the excess of colon cancer in some breast-ovarian cancer families is related to the I1307K mutation, we evaluated 264 Ashkenazi Jews from 158 families. Most of these individuals had either a personal or a family history of breast and/or ovarian cancer, and 19.3% (51 of 264) carried one of the recurrent BRCA1 (185delAG or 5382 insC) or BRCA2 (6174delT) mutations. We detected the APC I1307K mutation in 7% (11 of 158) of the Ashkenazi Jewish families and in 4.5% (12 of 264) of the individuals participating in these studies. Of the families studied, 26.6% (42 of 158) had at least one case of colorectal cancer in a first-, second-, or third-degree relative of the proband. Significantly, of the 12 individuals who possessed the I1307K mutation, none was diagnosed with colorectal cancer and none had a known first-, second-, or third-degree relative diagnosed with colon cancer. The results suggest that factors other than the I1307K mutation contribute to the increased incidence of colon cancer in Ashkenazi breast-ovarian cancer families. Our results emphasize that only a subset of Ashkenazi Jewish individuals with a family history of colorectal cancer should be viewed as candidates for genetic susceptibility testing for the I1307K APC mutation.

Exploring family relationships in cancer risk counseling using the genogram.

OBJECTIVES: The genogram is a tool that has facilitated counseling in family therapy and social work for many years. It is hypothesized that genograms may also be useful in genetic counseling, because they help the counselor to acquire more objective and consistent information from the client, as well as to incorporate family dynamics and psychosocial issues into the counseling approach. MATERIALS AND METHODS: A pilot study of genograms used as an adjunct to genetic counseling was performed at Fox Chase Cancer Center's Family Risk Assessment Program. A questionnaire was developed to elicit genograms from 38 women at risk for familial breast and/or ovarian cancer. After standard pedigree expansion, a series of questions was asked about the consultand's relationship with other family members, communication patterns within the family, attitudes toward genetic testing, family reactions to cancer, roles individuals play in the family, and significant historical or anniversary events. Relationships were defined by the consultand as close, very close, conflictual, fused and conflictual, distant, or estranged. RESULTS: The majority of relationship types reported by 38 individuals was "very close" or "close." Eighty-one % reported having close/very close relationships with their spouses, 83% reported close/very close relationships with their mothers, and 70% reported close/very close relationships with their fathers. The degree of familial cohesion as depicted by the genogram correlates positively with scores obtained on the standardized Social Adjustment Scale Self-Report (P = 0.01). CONCLUSIONS: Given the family-wide implications of genetic testing, the genogram may offer important guidance in family-targeted interventions.

Anxiety/uncertainty reduction as a motivation for interest in prophylactic oophorectomy in women with a family history of ovarian cancer.

Most women at familial risk for ovarian cancer must decide about prophylactic oophorectomy without conclusive genotypic information about their risk level. Some women with relatively low-risk profiles seek prophylactic oophorectomy or are recommended the procedure by their physicians, if they appear "cancerphobic." This study investigated the desire to reduce anxiety in relation to other factors associated with interest in prophylactic oophorectomy in a group of women with varying degrees of familial risk for ovarian cancer. Ninety-four women enrolled in an ongoing program for women with a family history of ovarian cancer received personalized risk counseling and were classified as having a sporadic, familial, or putative hereditary pedigree by a genetics counselor. Eligible enrollees were interviewed by telephone about current and future interest in prophylactic oophorectomy, perceived risk of ovarian cancer, severity of cancer anxiety, stress-related ideation, and reasons for and against surgery. Reduction of anxiety/uncertainty was the factor most strongly associated with current interest in prophylactic oophorectomy, independent of objective risk classification, perceived risk, severity of cancer anxiety, intrusive ideation, or other variables. Future interest in prophylactic oophorectomy was predicted by other perceived benefits of surgery. Current, but not future, interest in prophylactic oophorectomy appears motivated in part by seeking immediate relief from anxiety. Interest in prophylactic oophorectomy may fluctuate based on varying exposure to cues that trigger anxiety. Women seeking prophylactic oophorectomy, particularly those with lower-risk family pedigrees, should be offered options for anxiety management as part of informed consent for prophylactic oophorectomy.

Communicating genetic test results to the family: a six-step, skills-building strategy.

As the availability of tests to identify hereditary predisposition to chronic diseases continues to grow, a need has arisen to prepare individuals receiving genetic test results to share this highly sophisticated and value-laden information with other at-risk family members. Responding to this need, a communication skills-building intervention, based on Buckman's model of "Breaking Bad News," was developed for use in the setting of genetic testing for BRCA1 and BRCA2 mutations. Outcomes will include knowledge, attitudes, and health behavior on the part of both the proband and her first-degree relatives.

Two distinct origins of a common BRCA1 mutation in breast-ovarian cancer families: a genetic study of 15 185delAG-mutation kindreds.

We screened 163 women from breast-ovarian cancer-prone families, as well as 178 individuals affected with breast and/or ovarian cancer but unselected for family history, for germ-line mutations in exon 2 of BRCA1, by SSCP analysis and direct sequencing. A total of 25 mutations were detected. Thirteen of 64 Jewish Ashkenazi women and 2 non-Jewish individuals were found to possess the 185delAG mutation. Haplotype data for all 15 individuals, with markers intragenic to BRCA1, suggest that the Jewish Ashkenazi individuals share a common ancestry that is distinct from the lineage shared by the other two women. These data provide the first evidence of two distinct lines of transmission for the 185delAG mutation, only one of which has its origins in the Jewish Ashkenazi population. Our screening also uncovered 10 affected individuals with an 11-bp deletion at nucleotide 188 of BRCA1 (188del11), 4 of whom are Ashkenazi Jews. This is only the third reported mutation detected within the Jewish Ashkenazi population and may represent the second most common alteration in BRCA1 found in Ashkenazi Jews in the United States. The observed overrepresentation of specific mutations within a subgroup of the general population may eventually contribute to the development of inexpensive and routine tests for BRCA1 mutations, as well as to the elucidation of other contributory factors (e.g., diet, environment, and chemical exposures) that may play a key role in cancer initiation and development. The implications of the mutational data, as well as the role that founder effect, demographic history, and penetrance play in the resulting observed phenomena, are discussed.